Floating deck for liquid-storage tanks



April 21, 1931- J. H. wlGGlNs FLOATING DECK FOR LIQUID STORAGE TANKS Filed April 5, 1929 Patented Apr. 21, 1931 PATENT OFFICE JOHN' E. WIGGINS, OF TULSA, OKLAHOMA FLOATING DECK FOR LIQUID-STORAGE TANKS .Application led April 3,

This invention relates to floating decks for liquid storage tanks of the general type in which the closure for the annular space between the floating deck and the side wall of the tank comprises segmental shoe members that are arranged in sliding engagement with the inner face of the side wall of the tank, one design or style of floating deck of the general type mentioned being illustrated in H, my prior Patent N o. 1,662,225, dated March One object of my present invention is to provide a novel supporting means for the shoe members of a structure of the general 5 type mentioned, which insures the shoe members being maintained in substantially parallel relationship with the side wall of the tank and with the upper and lower end portions of said shoe members pressed against I said side wall.

Another object is to provide an inexpensive and serviceable mounting for the shoe members of structures of the general type mentioned, that comprises one set of springs for effecting the bodily movement of the shoe members inwardly and outwardly relatively to the deck, and a separate set of springs for causing the shoe members to rock or turn relatively to their supporting devices in such a way as to effectively counteract the tendency of the lower end portions of the shoe members to swing inwardly away from the side wall of the tank.

Another object is to provide a shoe member for structures of the general type mentioned whose tank wall engaging face is provided intermediate its upper and lower ends with a horizontally-disposed groove, recess or corrugation which decreases the area of 4u the shoe member that is held out of contact with the tank wall by the engagement of the shoe member with the rivets or horizontally-disposed shoulders on the tank wall when the shoe member travels upwardly and downwardly over said wall. Other objects and desirable features of my invention will be hereinafter pointed out.

Figure 1 of the drawings is a view looking towards the inner face ofthe side wall of the f tank, showing a portion of one of the seg- 1929. Serial N0. 352,169.

mental shoe members and the hanger which sustains or supports said member; and

Figure 2 is a vertical sectional view, taken on the line 2--2 of Figure l.

Referring to y the drawings which illustrate the preferred form of my invention, A designates the side wall of a tank that is used for storing oil or other liquid and B designates a deck that floats upon the liquid in the tank and covers the major portion of the surface of the liquid. The space between the side wall of the tank and the deck B is closed by a substantially gas-tight, expansible and contractile means that comprises a plurality of segmental shoe members C arranged vertically in sliding engagement with the inner face of the side wall A of the tank and which kare mounted on or carried by the deck B in such a way that they can move inwardly and outwardly relatively to the deck. The deck 7o B is provided with an upwardly-projecting rim D that issurrounded by the shoe formed by the segmental-shaped members C, and any suitable means can be used to close the space between said shoe and rim, such, for example, as a piece of substantially gas-tight fabric E that is attached to the top edge of the rim D and to the upper end portions of the segmental-shaped shoe members C.

One feature of my present invention consists of a supporting means for the shoe members C, which is of such design that it will eectively hold said shoe members in parallel relation with the side wall of the tank and with the upper and lower end portions of said shoe members pressed against saidside wall. Said supporting means can be constructed in various ways without departing from the spirit of my invention, but it will usually comprise shiftable supports F pivotally. attached to the upper ends of the shoe members C` and combined with springs or some other suitable means G that exerts pressure on said supports F in a direction to force the shoe members outwardly towards the side wall of the tank, and an independent means which exerts pressure on the shoe members C in a direction to hold the lower end portions of the shoe members pressed against. the side wall of the tank. In the 1GO form of my invention herein illustrated the independent means last referred to consists of springs H that are combined with the shoe members C and with the shiftable supports F in such a way that they cause the shoe members to rock or turn on their supports F in a direction to force the lower end portions of the shoe members outwardly towards the side wall of the tank, but I wish it to be understood that other means can be used to accomplish this same result without departing from the spirit of my invention.

In order that the various elements or parts of the supporting structure for the shoe members C will not be subjected to corrosion, or to the deleterious action of the liquid or gases confined in the tank, I arrange the shiftable supports F for the shoe members on the outside of the annular space between said shoe members and the rim D and construct said supports in the form of substantially elbowshaped levers or hangers whose upright legs are pivotally connected at their lower ends by pivots 1 to lugs or brackets 2 on the rim D of the deck, and whose horizontal legs project laterally or outwardly over the top edge of the rim D and are pivotally connected at their terminal ends by pivots 3 to the shoe members, as shown in Figure 2. I have only illustrated one of the hangers F, but it will be understood that in practice the rim D on the deck is provided with a plurality of such hangers arranged in spaced relation around the entire circumference of the rim.

The spring G, previously referred to, that is used to force the hanger outwardly or `to wards the side wall A of the tank, preferably consists of a coiled spring, as shown in Figure 1, mounted on the pivot 1 of the hanger and provided with two upwardly-proj ecting arms, one of which is attached to the upright leg of the hanger and the other to the rim D, said spring being so designed that the pressure which it exerts on the hanger F will decrease progressively as the outward movement of the hanger relatively to the rim D increases. The spring II previously referred to consists of a contractile spring which is attached at one end to the upper end of the hanger by means of a bracket or upwardly-projecting lug 4 on the upright leg of the hanger, and attached at its opposite end to a bracket 5 that projects upwardly above the pivot 3 of the shoe member, thereby exerting a force or pressure on the shoe member tending to turn the shoe member relatively to the hanger and force the lower end portion of the shoe member outwardly into snug engagement with the side wall of the tank. The bracket 5 is preferably arranged in overlapping relationship with the fabric E, previously referred to, so as to serve as a clamping member for said fabric and is secured to the upper edge portion of the shoe member by bolts or other suitable fastening devices 6, and the pin 3 which serves as the pivotal connection between the hanger and shoe member is arranged horizontally in the terminal portion of the horizontal leg of the hanger and in lugs 7 on the bracket 5 that embrace said terminal portion.

Due to the fact that the shoe member C is pivotally connected at its eXtreme upper end to the hanger F, there is a natural tendency for the lower end portion of the shoe member to swing inwardly away from the side wall of the tank, but the spring H or other means that is attached to the upper end of the shoe member at a point above its pivot 3, counteracts the natural tendency of the shoe member to assume the position referred to and co-operates with the hanger-actuating spring Gr to effectively hold the shoe member in substantially parallel relationship with 'the side wall of the tank and with both the upper and lower portions of said shoe member pressed against said side wall.

Another feature of my present invention which adds greatly to the efficiency of the structure and tends to prevent gases and vapors from escaping from the tank through the joint between the side wall A and shoe members C, consists in providing the tank wall engaging face of each shoe member C with a horizontally-disposed recess, groove or corrugation 8, as shown in Figure 2, so as to compensate for the rivet heads 9 and horizontally-disposed shoulders 10 on the seams in the side wall of the tank over which the shoe member travels. If the tank wall engaging surface of the shoe member were made straight throughout its entire height, a gap of considerable area would be formed between the shoe member and the tank side wall during the time the shoe member is traveling vertically over a horizontal row of rivet heads 9 on the side wall, thereby partially destroying the sealing effect of the shoe members on the tank side wall. By forming a horizontally-disposed groove or corrugation 8 in the shoe member, whose depth is equal to or in excess of the height of the rivet heads, I greatly decrease the area of the shoe member that is held out ofwcontact with the side wall when the shoe'fdmember is traveling over the rivet heads 9 .and shoulders 10, due, of course, to the fact'A that said groove or corrugation forms a pocketuin which the rivet heads are positioned during a portion of the vertical travel of the shoe member, said pocket being made of such length with relation to the distance between the horizontal row of rivets 9 and the adjacent shoulder 10 on the side wall, that there are always contacting surfaces of considerable area on the shoe member and side wall while the shoe is traveling over a horizontal seam or joint in the side wall. In other words, assuming that the shoe member is traveling upwardly over the side wall, the engagement iso' of the rivet heads 9 with the upper end portion of the shoe member forces the upper end portion of the shoe member inwardly, momentarily, away from the side wall during a portion of the upward travel of the shoe member, but as soon as the pocket or corrugation 8 in the shoe member comes into alignment with the rivets, the upper end portion of the shoe member will move outwardly back into engagement with the side wall, and by the time the rivets 9 start to pass out of the pocket, the upper end portion of the shoe member will have traveled over the shoulder 10 and moved into engagement with a portion of the side wall above said shoulder, thereby causing the shoe member to travel over the seam in the side wall without producing a joint that remains open for a considerable time and through which gases or vapors can escape from the interior of the tank.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a liquid storage tank, the combination of a side wall, a floating deck, a closure for the space between the side wall 'and the peripheral edge of the deck, comprising a shoe member that is adapted to engage said side wall, a shiftable support for said shoe member, means for rockably mounting said shoe member on said support, means for causing said support to move said shoe member outwardly into engagement with said wall, and a means separate and distinct from the means acting on said support, which exerts pressure on the shoe member in a direction tending to cause it to turn relatively to the support for the purpose of insuring good contact between the free end of the shoe member and said wall.

2. In a liquid storage tank, the combination of a side wall, a :floating deck, a closure for the space between the side wall and peripheral edge of the deck, comprising a shoe member that is adapted to engage said wall,

la shiftable support for said shoe member that moves it outwardly towards lsaid wall, a pivotal connection between said support and shoe member located-at the upper end of said shoe member, and a spring connected to said support and attached to the shoe member at a point above the pivot of same, for the purpose described.

3. In aliquid storage tank, the combination of a side wall, a iioating deck, a shoe member that is adapted to engage said side wall, a support for said shoe member pivotally kmounted on the deck, a pivotal connection between said shoe member and support located adjacent one end of said shoe member, a springthat exerts pressure on said sup-- port' in a direction tending to force the shoe member outwardly towards the side wall, and an independent spring combined with said shoe member and support for holding the-free end of said shoe member in engagement with said wall.

4. In a liquid storage tank, the combination of a side wall, a floating deck, a substantially gas-tight closure for the space between said side wall and the peripheral edge of the deck, comprising a shoe member that is adapted to slide over said wall, a hanger pivotally mounted on the deck and arranged on the outside of said closure, a pivotal connection between said hanger and the upper end portion of the shoe member, and springs located on the outside of said closure and combined with said hanger and shoe member in such a way as to hold both the upper and lower portions of the shoe member in snug engagement with said side wall.

5. In a liquid storage tank, the combination of a side wall, a iloating deck provided at its peripheral edge with an upwardlyprojecting rim arranged in spaced relation with said side wall, a pivotally mounted hanger on said deck provided with a portion that projects outwardly over the top edge of said rim, a shoe member adapted to slide on the inner face of said side wall, pivotally attached at its upper end to the outwardlyprojecting portion of said hanger, a spring that exerts pressure on the hanger ina direction tending to force the shoe member outwardly towards said side wall, and a spring connected to said hanger and attached to said shoe member at a point above the pivot of same for insuring the lower end portion of the shoe member contacting with said side wall.

6. In a liquid storage tank, the combination of a side wall, a floating deck provided at its peripheral edge with an upwardlyprojecting rim, a substantially elbow-shaped hanger pivotally mounted on said rim and arranged with its horizontal leg projecting outwardly over the top edge of said rim, a shoe member adapted to slide over the inner face of said side wall, a bracket attached to the upper end of said shoe member, a pivotal connection between said bracket and the outwardly-projecting leg of the hanger, and a contractile spring connected to said bracket and attached to the upper end of the hanger for moving the lower end portion of the shoe member towards said side wall.' Y

7. In a liquid storage tank, the combination of a side wall, a floating deck provided at its peripheral edge with an upwardlyprojecting rim, a substantially elbow-shaped hanger pivotally mounted on said rim and arranged with its horizontal leg projecting outwardly over the topedge of said rim, a

shoe member adapted to slide over the innerface of said side wall, a bracket attached to the upper end of said shoe member, a pivotal connection between said bracket and the outwardly-projecting leg of the hanger, a` contractile spring connected to said bracket' and attached to the upper end of the hanger, and a piece of substantially gas-tight fabric having one of its edges attached to said rim and its other edge interposed between said brack et and the upper end portion of the shoe member.

8. In a liquid storage tank, the combination of a side wall provided with horizontallydisposed seams, a floating deck, a substantially gas-tight closure for the space between said side wall and the peripheral edge of the deck, comprising a vertically-disposed shoe member provided in its wall engaging face with a horizontally-disposed groove, corrugation or pocket, a supporting'structure for said shoe member arranged on the outside of said closure, and springs combined with said shoe member and supporting structure for holding the upper and lower end portions of the shoe member pressed against said Wall when the shoe member moves vertically over the wall.

' JOHN H. W'IGGINS. 

